Waveguides are used to control a propagation of light from one element to another. Waveguides are used in image sensors, optical communications, opto-electric circuits, spectrum analysis devices as well as other technologies. Diffraction gratings are used in waveguides to separate different wavelengths of a light beam or to combine different wavelengths into a single light beam.
A transmission grating separates an incoming light beam into component wavelengths by refracting the incident light beam. An angle of refraction is determined in part by the wavelength of the component wavelength. Similarly, the transmission grating combines light of different wavelengths into a single output light beam by refracting the incident light so that multiple wavelength input are combined into the single output light beam.
A reflecting grating separates the incoming light beam into component wavelengths by reflecting the incident light beam. An angle of reflection is determined in part by the wavelength of the component wavelength. Similarly, the reflective grating combines light of different wavelengths into the single output light beam by reflecting the incident light so that multiple wavelength input are combined into the single output light beam.